| 摘要 |
PURPOSE:To detect noise caused by changes in the brightness due to characters on a road or the like by spatially differentiating video signal in the scan direction in a bird's-eye view photographing of the road to make a noise signal when a feature signal on the same scan line continues for a specified cycle. CONSTITUTION:In a bird's-eye view photographing of a road, a video signal is scanned from left to right or top to bottom in the direction of crossing a traffic lane and spatially differentiated in comparison of a difference from an adjacent sample value with threshold to determine a feature signal on the same scan line. A fixed value decision device 3 receives the feature signal and the number of the scan line from a feature signal generator 1 and compares the feature signal corresponding to an area to be photographed with a signal from a feature value register 2. When they are equal with each other, the value of a continuous counter 4 is incremented by 1 while when they are not, the value of the counter 4 is made at 1. When the value of the counter 4 becomes equal to the set value in a continuous value buffer 5, the value of the feature value register 2 is stored into a memory section of a noise buffer 7. |
